1. Field of the Invention
The present invention relates to a means to maintain the position of two or more energetically moveable objects in a spaced relation vis-a-vis each other. More specifically, the present invention in a preferred embodiment relates to a system to maintain two marine seismic sources in a preferred, spaced orientation during continuous operation.
2. Description of the Prior Art
Marine seismic exploration often utilizes seismic sources, airguns or waterguns, pulled behind a boat over submarine horizons of perceived interest. Upon actuation, these sources create a strong, primary pressure pulse which is useful in interpreting the strata comprising the sea floor.
To enhance this primary pulse, and hence advance the geological interpretation of the sea floor, it has become common practice to simultaneously fire a number of these seismic sources. In this connection, it has been discovered that marine seismic sources selectively positioned with respect to each other optimize the creation of the primary pulse while minimizing the creation of undesired secondary pulses. This optimization, generally known as the "cluster effect," relics on spacing between the sources given the parameters of volume, pressure, and depth.
In practice, however, realization of the benefits of the "cluster effect" has been difficult since seismic sources, due to the strong energy pulses created during actuation and recoil, are prone to substantial and energetic movements with respect to each other. Furthermore, the air bubbles created upon actuation of the marine acoustic generator ultimately collapses, forcing the sources together and thereby inducing significant damage on the gun lines and peripheral equipment.
Prior mechanical clamping systems have been designed to address this issue. Such clamping systems, however, if strong enough to prevent substantial movement of the sources with respect to each other, have generally been bulky and contribute to substantial drag on the towing source. In some instances, this drag may be of a sufficient magnitude as to foreclose their use as a towed array altogether.
Systems which are not as massive, and hence more streamlined, having been generally unable to achieve the rigidity and spacing necessary for optimization of the "cluster effect". Moreover, such systems are readily damaged through consecutive recoils of the seismic sources during operation.